1. Field of the Invention
The present invention relates to an improved method for homopolymerizing or copolymerizing vinyl chloride and more specifically to a method for preventing the adhesion of polymer to the inner wall of a polymerizer or the like during polymerization of vinyl chloride.
2. Description of the Prior Art
When vinyl chloride is homopolymerized Or copolymerized with another monome copolymerizable with vinyl chloride (hereinafter simply referred to as "polymerized or polymerization"), there is observed adhesion of a polymer to portions of devices such as the inner wall of a polymerizer, a reflux condenser, a stirring blade, a baffle and a variety of accessory pipings and/or connections thereof which are brought into contact with the monomers during the polymerization. For this reason, various problems arise. For instance, the cooling capacity of the polymerizer is greatly impaired and the polymer once adhered to these devices and then peeled off is mixed in the resulting homopolymer or copolymer (hereinafter referred to as "product(s)") to thus lower the quality of the products. Therefore, it is a general practice that the subsequent polymerization operation must be started after each polymerization operation is finished and after the polymerizer is cleaned. However, this requires a great deal of labor and time and this in turn results in the reduction of the working ratio of the polymerizer and an increase in the cost of the products.
Under such circumstances, there have been proposed a variety of methods for preventing the adhesion of polymers to the inner wall of polymerizers or other portions through the application of an agent to these portions.
These methods are effective for preventing the adhesion of polymers, but they conversely suffer from a variety of drawbacks such as a decrease in the polymerization speed and deterioration of physical properties of the resulting products. Thus, these methods cannot be satisfied from the industrial standpoint. Moreover, many attempts have been directed to the development of methods which do not impair the polymerization speed and physical properties of the products, but these methods do not likewise provide a satisfied polymer adhesion-inhibitory effect. For instance, there have been proposed methods which comprise applying co-condensate of resorcin and aldehyde (see KOHYO Nos. Sho 57-502169 and Sho 57-502170), but these methods are still insufficient in the polymer adhesion-inhibitory effect.